diff --git a/core/lib/Drupal/Core/Database/Driver/mysql/EntityQuery/Condition.php b/core/lib/Drupal/Core/Database/Driver/mysql/EntityQuery/Condition.php
new file mode 100644
index 0000000..05d82fe
--- /dev/null
+++ b/core/lib/Drupal/Core/Database/Driver/mysql/EntityQuery/Condition.php
@@ -0,0 +1,12 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Database\Driver\mysql\EntityQuery\Condition
+ */
+
+namespace Drupal\Core\Database\Driver\mysql\EntityQuery;
+
+use Drupal\Core\Database\EntityQuery\Condition as EntityQueryCondition;
+
+class Condition extends EntityQueryCondition { }
diff --git a/core/lib/Drupal/Core/Database/Driver/pgsql/EntityQuery/Condition.php b/core/lib/Drupal/Core/Database/Driver/pgsql/EntityQuery/Condition.php
new file mode 100644
index 0000000..938ed39
--- /dev/null
+++ b/core/lib/Drupal/Core/Database/Driver/pgsql/EntityQuery/Condition.php
@@ -0,0 +1,47 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Database\Driver\pgsql\EntityQuery\Condition
+ */
+
+namespace Drupal\Core\Database\Driver\pgsql\EntityQuery;
+
+use Drupal\Core\Database\EntityQuery\Condition as EntityQueryCondition;
+
+class Condition extends EntityQueryCondition {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function addConditionToContainer(&$conditionContainer, $field, $condition) {
+    if (isset($condition['where']) && isset($condition['where_args'])) {
+      $conditionContainer->where($condition['where'], $condition['where_args']);
+    }
+    else {
+      $conditionContainer->condition($field, $condition['value'], $condition['operator']);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function translateCondition(&$condition, $case_sensitive) {
+    // For PostgreSQL for which the condition arguments need to have case
+    // lowered to support not case sensitive fields.
+    if (is_array($condition['value']) && $case_sensitive === FALSE) {
+      $condition['where'] = 'LOWER(' . $condition['real_field'] . ') ' . $condition['operator'] . ' (';
+      $condition['where_args'] = [];
+
+      $n = 1;
+      foreach ($condition['value'] as $key => $value) {
+        $condition['where'] .= 'LOWER(:value' . $n . '),';
+        $condition['where_args'][':value' . $n] = $value;
+        $n++;
+      }
+      $condition['where'] = trim($condition['where'], ',');
+      $condition['where'] .= ')';
+    }
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Database/Driver/sqlite/EntityQuery/Condition.php b/core/lib/Drupal/Core/Database/Driver/sqlite/EntityQuery/Condition.php
new file mode 100644
index 0000000..eb79804
--- /dev/null
+++ b/core/lib/Drupal/Core/Database/Driver/sqlite/EntityQuery/Condition.php
@@ -0,0 +1,12 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Database\Driver\sqlite\EntityQuery\Condition
+ */
+
+namespace Drupal\Core\Database\Driver\sqlite\EntityQuery;
+
+use Drupal\Core\Database\EntityQuery\Condition as EntityQueryCondition;
+
+class Condition extends EntityQueryCondition { }
diff --git a/core/lib/Drupal/Core/Database/EntityQuery/Condition.php b/core/lib/Drupal/Core/Database/EntityQuery/Condition.php
new file mode 100644
index 0000000..0dbefd0
--- /dev/null
+++ b/core/lib/Drupal/Core/Database/EntityQuery/Condition.php
@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Database\EntityQuery\Condition.
+ */
+
+namespace Drupal\Core\Database\EntityQuery;
+
+/**
+ * Implements entity query conditions for SQL databases.
+ */
+class Condition {
+
+  /**
+   * Adds the condition to the condition container.
+   *
+   * @param $query
+   *   The query object this conditional clause belongs to.
+   * @param string|\Drupal\Core\Entity\Query\ConditionInterface $field
+   * @param array $condition
+   *   The condition array.
+   */
+  public static function addConditionToContainer(&$conditionContainer, $field, $condition) {
+    $conditionContainer->condition($field, $condition['value'], $condition['operator']);
+  }
+
+  /**
+   * Translates the string operators to SQL equivalents.
+   *
+   * @param array $condition
+   *   The condition array.
+   * @param bool|null $case_sensitive
+   *   If the condition should be case sensitive or not, NULL if the field does
+   *   not define it.
+   */
+  public static function translateCondition(&$condition, $case_sensitive) {  }
+
+}
diff --git a/core/lib/Drupal/Core/Entity/Query/Sql/Condition.php b/core/lib/Drupal/Core/Entity/Query/Sql/Condition.php
index f34df0e..9aea72d
--- a/core/lib/Drupal/Core/Entity/Query/Sql/Condition.php
+++ b/core/lib/Drupal/Core/Entity/Query/Sql/Condition.php
@@ -7,10 +7,11 @@

 namespace Drupal\Core\Entity\Query\Sql;

-use Drupal\Core\Entity\Query\ConditionBase;
-use Drupal\Core\Entity\Query\ConditionInterface;
+use Drupal\Core\Database\Database;
 use Drupal\Core\Database\Query\SelectInterface;
 use Drupal\Core\Database\Query\Condition as SqlCondition;
+use Drupal\Core\Entity\Query\ConditionBase;
+use Drupal\Core\Entity\Query\ConditionInterface;

 /**
  * Implements entity query conditions for SQL databases.
@@ -28,6 +29,8 @@ class Condition extends ConditionBase {
    * {@inheritdoc}
    */
   public function compile($conditionContainer) {
+    $entityQueryCondition = Database::getConnection()->getDriverClass('EntityQuery\\Condition');
+
     // If this is not the top level condition group then the sql query is
     // added to the $conditionContainer object by this function itself. The
     // SQL query object is only necessary to pass to Query::addField() so it
@@ -46,8 +49,9 @@ public function compile($conditionContainer) {
       else {
         $type = strtoupper($this->conjunction) == 'OR' || $condition['operator'] == 'IS NULL' ? 'LEFT' : 'INNER';
         $field = $tables->addField($condition['field'], $type, $condition['langcode']);
+        $condition['real_field'] = $field;
         static::translateCondition($condition, $sql_query, $tables->isFieldCaseSensitive($condition['field']));
-        $conditionContainer->condition($field, $condition['value'], $condition['operator']);
+        $entityQueryCondition::addConditionToContainer($conditionContainer, $field, $condition);
       }
     }
   }
@@ -80,10 +84,16 @@ public function notExists($field, $langcode = NULL) {
    * @see \Drupal\Core\Database\Query\ConditionInterface::condition()
    */
   public static function translateCondition(&$condition, SelectInterface $sql_query, $case_sensitive) {
-    // There is nothing we can do for IN ().
+    // There is nothing to do for IN () queries except for PostgreSQL for which
+    // the condition arguments need to have case lowered to support not case
+    // sensitive fields.
     if (is_array($condition['value'])) {
+      $entityQueryCondition = Database::getConnection()->getDriverClass('EntityQuery\\Condition');
+      $entityQueryCondition::translateCondition($condition, $case_sensitive);
+
       return;
     }
+
     // Ensure that the default operator is set to simplify the cases below.
     if (empty($condition['operator'])) {
       $condition['operator'] = '=';